Back story - Wanted cast wheels so I got a set front and rear from a gs450. Front was a near drop in. The rear was 2.15 and required all sort of screwing around with spacing to avoid a pull to the side and still line up the sprockets. After messing with it off and on all last spring I finally had it jerry rigged to go but all the jerry rigging was hideous and made removal a PITA. I later learned thats because the gs550 rear wheel is the replacement others were using.

So...I switched the rear 450 for the rear 550. Its great. Practically a drop in replacement. 39mm spacer on the left, 19mm on the right. Chain is straight, rear brake housing fits perfectly. Only problem now is I got a wee wobble coming from the front wheel now. Im geussing the line of travel has shifted oh so slightly to the right with the 550 wheel versus the 450 wheel. If any of you running this cast wheel setup have occassion to have your front wheel off Id much appreciate the measurements of the spacers you're using. As of now Ive got my front 450 wheel centered as best I can tell 33mm spacers on both sides but the bike ever so slightly favors to the left. Any pressure (extremely light pressure) on the bars to kind of "equalize" it and it tends to then want to go right.  Let off pressure and it goes back to favoring leftward drift.

Dealt with spacing all of last spring...dont really want to repeat it all over again.
Once I do get this done Im going to throw up a Cast wheel post in the tech section with definitive measurements and directions so others dont have to do this geussing and constantly removing the wheels trying spacer sizes in 1mm increments at a time.

  A GR 650 had those same wheels I don't know if is the size is different,But they only sold the bike 2 years here so would probability be hard to find.